In 2008
for the first time, the
team split
the birds into two groups headed for two wintering
areas: the original winter home at Florida's Chassahowitzka NWR and
a second home at Florida's St. Marks NWR.

Dividing the Flock

Why split
the group? There are many threats to Whooping
cranes, so the Whooping Crane Recovery Team and the
Whooping Crane Eastern Partnership wanted to test a new site by dividing
the flock. They could not forget loss of 17
of the 18 Class of 2006 cranes at Chass after a severe storm in
February 2007.
That's why St. Marks was added as a second winter home in 2008. More
crane habitat is available at St. Marks and storm-driven tides are
rare.
Splitting
the
flock between
the two sites cuts the risk of
another
loss
of
an entire
generation
such as happened with the Class of 2006. With so many adults in the
flock now, they believe it will be safer for
the
crane-kids
to
have
more
space and privacy from the territorial older birds. (The older birds
often return to "their" winter pen site for free food — and
may pick on the youngest birds.)

How
does the team decide who goes where? They consider five important
factors: gender, siblings, dominance, genetic value, and migration
knowledge.
That means:

Each
group should have the same number of females.

Any *siblings
of the opposite gender will be kept together; siblings of the same
gender will be apart.

Birds
in each group must get along with one another and have a balanced dominance
order. Birds with social problems must be evenly divided or separated.

Genetically
valuable birds must be evenly divided.

Birds
that missed parts of the fall migration due to dropping out or not
being able to fly on some of the fly days should be evenly divided.

Try This: Journal or Discussion Questions

The
group that winters at Chass will need to fly a greater distance in
the spring than the group from St. Marks. Could this affect the
decision of how the birds are divided? If so, how?

The
final decision for which birds go in each group will be made by
a teleconference call among WCEP experts when the Team nears the
end
of migration. Why
do you think many opinions are being considered?

*Scientists
have to do some guess work. Some experts believe it is more important
to split any brother-sister cranes. Then
if something bad happens to one group, the whole family isn't
lost
together.
Because
they were
reared together, the brother and sister would view each other
more as siblings and not be likely to pair with each other later.
Others say
it is more
important
to
separate
siblings
that
are
the same gender.
Why is the question of gender of such great concern? How might the
scientists get more information to help their decision making?

When
your teacher assigns seats or groups in your classroom, how do you
think those choices are made?